If scientists ever found evidence that we are not alone in the universe, what would happen next?

I posed that question to Bill Diamond, CEO of the SETI Institute in 2023 during an interview for our podcast Are We There Yet?.

“Well,” he told us “we’d probably call a press conference.”

For what is likely to be the most consequential scientific discovery for humanity, the answer to how we would tell the world we’re not alone in the universe was a press conference.

As a journalist covering space for more than a decade, I’ve covered hundreds of press conferences. They’re usually pretty mundane – a mission status update, the announcement of a new launch contract. Sometimes, they can be quite exciting, like when NASA named the crew of the Artemis II moon mission.

But news of cosmic neighbors would certainly outweigh even that excitement. It was hard to think about how I might cover that press conference. Thinking about that day, as a journalist, is the catalyst to this podcast.

For most of human history, we have asked “are we alone?” Centuries ago, it was the philosophers and the priests asking the question. These days, it’s the scientist leading the charge to find the answer.

And everyone in between is curious, probably even you, if only just a little, of what that answer might be.

We’re on the verge of answering that question. Arrays of massive radio telescopes are listening to the vast universe for any signs of some other species saying hello. We’re peering into the atmospheres of far-away planets, ones that exist both inside and outside our own solar system for chemical signs of life — be it breaths, or pollution, or even farts, on another world. Closer to home, robotic explorers are digging up what they hope may be signs of ancient microbial life on one of our closest celestial neighbors.

What happens when we find the answer?

For this podcast, I reached out to all sorts of experts: scientists, scholars, religious leaders, anthropologists, politicians and journalists. They all told me the same thing — they expect an answer. Not proof of little green men or flying saucers, but real, definitive evidence of something and sooner than most people think.

It’s not a matter of if. It’s a matter of when.

But what almost none of them could tell me, definitively, is what happens next. Who announces such a finding? What would the discovery do to us humans? How would it change our cultures, our religions, our understanding of science as we know it now? Would we even believe it?

And what happens in the murky, sprawling weeks or even years between “we saw something strange” and “we are confident this is real?”

This podcast follows the people that are trying to answer those questions before that day arrives, and we find that the plan is far less finished than you might assume.

Modern efforts to search for life in the universe can be traced back to one boy.

Frank Drake was born on May 28, 1930 in Chicago. His mother was a music teacher and his father a chemical engineer. Growing up during the Great Depression, Frank would hear stories from his father about the night sky – about other worlds out there, like the baron planets in our solar system.

“But Dad, who was like six or eight years old at the time, he didn't know that, and he thought that my grandfather was referring to other worlds like Earth,” recalls Nadia Drake, a science journalist and daughter of Frank. “He started to wonder, did those places really exist, and if so, could he find them, and could we maybe actually communicate with whomever lived there.”

Frank Drake studied astronomy, getting his PhD from Harvard in 1958 as one of the first radio astronomers.His first job was at the National Radio Astronomy Observatory in Green Bank, West Virginia.

It was there, in 1960, where he would get that chance to try and detect those other civilizations in our universe that young Frank wondered about. That year, he convinced the observatory director to give him $2,000 to conduct the first search for life outside our own planet.

He named his search Project Ozma — after the queen in L. Frank Baum’s Land of Oz, a series Frank Drake loved as a kid.

“Oz is a strange land full of strange and exotic creatures, and he imagined that the worlds that he was searching for may be similar in that sense,” Nadia Drake said. “He wanted to bring Oz back into life.”

To search for that land full of strange and exotic creatures, for six hours a day from April to July 1960, Frank pointed an 85-foot antenna at two stars some 11 light years away, or about 64 trillion miles from Earth.

The two target stars were much like our own sun. “He reasoned that if those stars had planets in orbit around them, as the sun does, and if those planets were anything like Earth, with civilizations that were anything like ours, then they would be releasing distinctly artificial radio signals into the cosmos,” Nadia Drake told me.

Frank Drake calculated that his telescope could detect those signals. So that’s what he tried to do – he listened around those two stars.

He was looking for someone just like us. To do that, he was listening for a very specific radio frequency. One he thought an alien civilization would use to say “Hello! We’re over here!”

The team used a chart recorder – an instrument that uses a pen to draw squiggles that correspond to a signal on a roll of paper. They used it to track any cosmic blips that would indicate that cosmic greeting and a loudspeaker to let them know if there was anything worth listening to.

But there was silence. Frank didn’t find that strange land he hoped to find as a kid. Our galaxy, it seemed, was quiet.

And we were alone.

The experiment, however, wasn’t considered a failure. It marked the first time anyone conducted a Search for Extraterrestrial Intelligence – the beginning of the era of SETI.

A year after Project Ozma, Frank Drake was asked to convene a meeting by the National Academy of Sciences specifically about the search for life, at the same observatory he used to carry out that groundbreaking search. It was a new field of study. So Frank invited everyone he knew interested in the topic – that turned out to be about a dozen people.

Despite the small size, Frank needed to make the most of the conference. He sketched out an agenda he thought might be worth discussing over the next three days.

“When he looked at the list of discussion topics, he realized that if he organized them in the form of an equation,” said Nadia Drake. “He just wrote down his meeting agenda in the form of an equation, just put it on the chalkboard, and that kicked off everything.”

The formula aimed to calculate the number of detectable civilizations in the Milky Way Galaxy. It would be known as the Drake Equation and it single handedly shaped the trajectory of efforts to search for life beyond our own planet.

The Drake equation isn’t something you can solve – at least not yet. It’s an estimation of just how many civilizations might be out there. It “tells you how many detectable civilizations there are in the Milky Way galaxy based on the values that you put in for seven variables, and you're just going to multiply all of these variables together,” said Nadia Drake. When you do, you get N, or the estimation of the number of civilizations in the galaxy.

The Drake Equation as written is:

N = R* × fp × ne × fl × fi × fc × L

The first variable R* is the rate of new star formation – how many new stars are born each year? Variable fp is the fraction of those stars with planetary systems, ne is the number of planets per system with an environment suitable for life. The fraction of suitable planets on which life appears is fl, and fi is the fraction of those planets on which intelligent life emerges. The final two variables are fc – the fraction of civilizations that develop technology that produces a detectable signal and L – the average length of time such civilizations produce those signs of life.

“You can kind of see how you're starting with something that's really very big, and just breaking it into smaller and smaller things: stars, planets, life, intelligence, technology,” said Nadia Drake. “You end up multiplying it all together, and you get this number that tells you how many detectable civilizations there are. We know there's at least one.”

That’s us. Planet Earth. Human beings. N is greater than or equal to 1.

When Frank Drake wrote that equation in 1961 there was only one variable that he kind of knew the value to – that was the rate of formation of stars. Everything else would have been just a guess.

But since 1961, our understanding of the equation’s variables have increased exponentially.

“We now know the answers to some of those questions pretty well,” said Josh Colwell, a planetary scientist and dean of the College of Sciences at the University of Central Florida.

“We know how many stars are in the Milky Way galaxy, we know a pretty good census of what kinds of stars there are.. We know a lot more now than we did even a few decades ago about how many planets there are,” he said. “So, with a whole bunch of those parameters we’ve got actual numbers that we really know what they are.”

The confirmation of exoplanets has been the biggest driver in getting a better answer to the Drake equation. Exoplanets are planets outside our solar system that orbit other stars — that’s the variable fp that asks the fraction of stars that have planets.

In the time of the formation of the Drake equation that confirmed number was zero. It was just a hypothesis that there were other planets orbiting other stars. But now, some 65 years later, scientists have confirmed over 6,000 and are now pretty confident that every star has planets.

So when you look up tonight at all those stars in the sky, imagine each of those stars having a handful of planets orbiting it.

In our Milky Way Galaxy Alone, there are billions of stars. That means there are trillions of planets. Surely there’s got to be one that’s just like ours — one with the potential to harbor life. Maybe one that’s at a distance from its star that’s not too hot or not too cold. One that has oceans, oxygen, and plants. One that has living organisms just like ours.

With that many potential planets, why haven’t we found anyone yet?

That vast contradiction is highlighted in what’s known as the Fermi Paradox. Quite simply, it asks: where is everyone?

There are a number of reasons why we haven’t found anyone yet. Maybe there are plenty of civilizations out there, they just haven’t figured out a way to travel to us yet. Or maybe it’s just a quiet time in galactic history. There also could be civilizations out there that just don’t want to be found.

“Or maybe civilizations never actually get to that point,” where they can travel to other star systems, said Colwell. “That gets to this concept called the Great Filter, which says something happens that prevents life from getting to the point where it could colonize the galaxy, so to speak.

The Fermi Paradox seems like a buzzkill for anyone searching for life outside our own planet. Some argue it should be taken with caution — it comes to a cast conclusion using limited observations. It’s like saying alligators don’t exist because you live in Colorado and never saw one in your backyard. Well they do exist. And as a Floridian I’ve seen plenty in my backyard.

Still, thousands of scientists are hard at work, each day, scanning the skies for any signs of life out there and chasing the day that they may one day hear something.

To those people, the Fermi Paradox is not a discouragement. It’s a call to action and underscores how important these efforts are to collect more data and eventually break the silence.

In 1960, during Frank Drake’s listening experiment, his team thought they heard something. And for that brief moment, Drake thought he made the discovery of a lifetime. He recalled that moment in an interview with the SETI Institute decades later.

“When you see that, and you think you're sure you have detected another civilization, you feel a very special emotion. It is different from all other emotions” he said. “I can't really describe it to you, but it's an emotion of elation, in a sense, that you are now part of some much greater world of knowledge and activity, and you have sort of gone through a door into a world of new facts, phenomena, creatures that populate our universe. It's a very powerful motion because you sense that what you're seeing is going to change all of history, and I think for the better.”

“When We Find Them” is a new limited podcast series from Central Florida Public Media that looks at our search for life in the universe and the not so finished plan to tell the world what we find.

We’ll look at our current efforts to search for life, the protocols in place to confirm such an extraordinary finding, and look at how we – as humans – may react when our entire worldview changes.